Automated parking systems are known in the art for many years. One of their goals is to increase the number of parked vehicles in a given parking space, either having a single story or multi-story facility. Converting of an existing traditional parking space into an automated parking space requires, among others, installation and operation of location and navigation means that will enable automated mobile means to load an incoming vehicle at a loading position and transport it to an intended parking area at the beginning of the parking period and to pick a parking vehicle from a given parking space and move it to an exit location at the end of the parking period, as well as enable the automated system to transport a parked vehicle from its current parking area to another, pre-defined parking area.
According to solutions known in the art, elements of the automated parking system that travel through the parking space are directed along route guiding means of electrical wires or conduits that are installed underneath the floor's surface. These wires emit radio-frequency (RF) transmissions at a low energy level. A corresponding receiver is installed on the traveling unit. This receiver is configured to sense the RF transmission and to indicate when the sensor has deviated from traveling substantially above the transmitting wire to the left or to the right. However, this method requires installations that involve either placement of the RF wires during the installation of the respective parking floor or entering the wire into an existing floor. Therefore, when this method is to be used in traditional drive-through parking facilities that are about to be converted to automated parking facilities, only the latter method of installation of the wire is applicable. However, drilling of grooves in an existing floor in order to bury RF transmitting wires along the travel paths may be not only very expensive and time-consuming, but may also require careful work in order not to damage other under-surface installations and in order to avoid risk of damaging constructive elements while performing the grooves. Therefore, there is a need for a method that will enable navigation of a transporting tool along predefined paths that does not involve under-surface installations in the floors.
Known automated parking facilities typically use one of two main approaches for parking vehicles. In the first approach, parked vehicles are placed in long rows where one vehicle is placed with its front bumper very close and even touching the rear bumper of the vehicle in front of it. This parking method may be denominated “tandem mode”. When one row is filled, the next row will be occupied on the left or the right of the previous one. In the second approach, parked vehicles are placed “side by side” next to a vehicle on the left or the right of the parked vehicle along column lines. This parking method may be denominated “side-by-side mode”. In both approaches, the amount of vehicles parked per area unit depends on the sizes of the vehicles and on the accuracy of movement and placement/pick-up of the automated parking system.
The first parking approach requires that the transporting tool which transports the vehicle will have the ability to move, at least in the final stage of parking (and, accordingly, in the first stage of pulling out from parking) in a direction that is perpendicular to the longitudinal dimension of the parked vehicle. The second approach requires that the transporting tool which transports the vehicle will have the ability to move, at least in the final stage of parking (and, accordingly, in the first stage of pulling out from parking) in a direction that is parallel to the longitudinal dimension of the parked vehicle. In this description, the longitudinal dimension of a vehicle is referred to the dimension that is parallel to the direction of driving of the vehicle when it goes along a straight line. A central longitudinal imaginary line is referred to as the Imaginary line that is parallel to the direction of driving of the vehicle when it goes along a straight line and passes substantially in the center of the width dimension of the vehicle.
Some known methods of transporting a vehicle through the parking facility in an automated parking system involve lifting the car, typically through its wheels, to minimize risk of damage to the car, and after the car has been lifted from the floor, transporting it on the transporting tool according to the parking scheme to its parking location. When the parked car is about to be lifted from the floor by lifting its wheels, there is a need to adjust the distance between the lifting elements of the transporting tool to properly meet the wheels of the parked car. The adjustment need to address both different longitudinal distances between the front and rear axles/wheels and different lateral distances between the left and right pairs (or more than pairs) of wheels, in different car models.
There are two main methods of approaching a car to be lifted for later transporting it in the parking facility. According to the first method, the transporting tool rolls between the left and right wheels substantially along the longitudinal axis of the car, underneath the bottom of the car, and the lifting elements approach their respective wheels from the center longitudinal line of the car outwardly left and right. According to the second method, the transporting tool approaches the vehicle from the side, moving substantially perpendicular to the vehicle's longitudinal axis and is configured to provide lifting means that extend from the transporting tool perpendicular to the longitudinal axis of the vehicle. These lifting means need to extend from one side of the vehicle at least so as to reach the wheels of the vehicle on its other side. Accordingly, a transporting tool operating according to the second method is required to be equipped with side-extending supports to the floor, or be equipped with a counter-weight, in order to provide balancing means for the transporting tool when a vehicle is lifted and carried. Transporting tools operating according to the second method typically use a single lifting means for each lateral pair of wheels of the vehicle. For example, such lifting means may comprise a pair of parallel fork teeth spaced apart from each other enough to allow passing of each of the fork teeth on different sides of a wheel of a car without touching the wheel and close enough to each other to have the wheel held safely between the fork teeth when the fork is lifted from the floor.
In order to allow for the required adjustment of the location of each of the lifting elements with respect to its respective wheel in a transporting tool operating according to the first method, the transporting tool needs to be located accurately enough with respect to the vehicle to be carried. The required accuracy includes accurate enough distance between the front and rear lifting means, to match the distance between the front and rear axles of the vehicle. Further, the transporting tool needs to be placed centered with respect to the center longitudinal line of the vehicle and aligned with it accurately enough. The term accurate enough, as is used in this description, means accuracy that ensures that the vehicle with respect to which the accuracy is measured is safely placed on the transporting means and safely carried with it across any maneuver that may be required during the transportation of the vehicle. Accordingly, slow moving transporting means may allow for less accuracy, while fast moving transporting means may require higher level of accuracy due to lower tolerance for inaccuracy of placement of the vehicle on the transporting means due to higher mechanical forces acting on the carried vehicle during maneuvering of the transporting means. Another consideration that may have implication on the required accuracy of the transporting tool is the degree of compactness of utilization of a given parking area, meaning the ratio between the total area covered by parked vehicles in a given parking space and the total area of that parking space. The higher the ratio is (approaching 1), the higher need to be the accuracy of the transporting tool. The operational accuracy of a transporting means may be evaluated or measured with respect to at least to different reference frames. One reference frame is the vehicle to be carried, as discussed above. The other reference frame may be the parking space, with respect to which the transporting tool navigates when transporting a vehicle or when moving to do that. Each of the reference frames may dictate different levels of accuracy and each of the requirements may be addressed using different measuring means, location identification means and the like. For example, the accuracy of location of the transporting tool with respect to the vehicle before it is being lifted may dictate tolerance of no less than +/−2 cm, while the accuracy of location of the transporting tool with respect to traveling paths in the parking space may dictate tolerance of no less than +/−2.5 cm.
Several methods and devices are known in the art for measuring the relative locations of a lifting element with respect to its respective wheel(s). Once these respective locations are known, adjustment of the location of each of the lifting means can take place. The distances between left wheels and right wheels in vehicles that are expected to be parked in automated parking facilities vary between 130 cm and 190 cm, center to center, that is—relatively small variations. Accordingly, in several lifting methods and means known in the art, the lifting elements are planned and operated to be indifferent to this dimension, that is the solution for addressing lateral distance variations between front and/or rear wheels is actually built to provide a single answer to the entire range of lateral dimensions of the vehicles to be parked, without needing any adjustment, as long as the center longitudinal line of the transporting tool substantially coincides with that of the vehicle. Addressing the longitudinal variations, however, is more complicated, since the longitudinal variations of the longitudinal distance between the front and rear axles of vehicles that are expected to park in an automated parking facility are much bigger than the lateral variations. For example, the longitudinal distance between the front and rear axles may extend from 185 cm to 370 cm, center to center, according to some embodiments aimed to serve for parking cars and small trucks and, according to other embodiments, up to few meters in applications such as truck and bus automated parking systems.
Some solutions known in the art provide a transporting tool with an ability to extend or retract along its longitudinal dimension. Once the exact distance between front and rear axles has been acquired or measured or otherwise obtained, the transporting tool may position one pair of lifting elements aligned with one pair of wheels, for example the front wheels, and then adjust the distance between the front and rear lifting elements to match the distance between the front and rear wheels by extending or extracting, as may be needed. Such solution suffers of several drawbacks. First, it is typically limited in the range of change of the distance between the front and rear wheels. Second, this solution typically increases the complexity and price of the transporting tool due to the need to provide an extendible central element that is also suitable for supporting the typical mechanical loads exerted on such a central element especially during movement with loads such as a vehicle. Finally, a transporting tool functioning according to this solution has a dictated minimal length that is at least somewhat longer than the distance between the front and rear wheels. This length, in turn, dictates the maneuverability of the transporting tool and specifically its minimal turning radius, which is a major feature required in automated parking systems. For example, limited maneuverability limits the ability of such transporting tool to accurately track a traveling path and specifically its ability to quickly recover this path when the transporting tool deviates from that path. There is a need for a transporting tool that will maintain adjustment capability to large range of varying lengths of vehicles along with relatively high maneuverability.